Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

625
FXUS63 KLOT 172341
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
641 PM CDT Tue Mar 17 2026

.KEY MESSAGES...

- A clipper-like system will lead to a coating of snow tonight
  through Wednesday morning. Untreated surfaces may become
  slippery.

- Another clipper system may deliver rain showers Wednesday
  night into Thursday morning.

- Temperatures will warm toward the 60s to locally lower 70s
  Friday and Saturday. A cold front will move through the area
  at some point on Sunday.

&&

.DISCUSSION...
Issued at 126 PM CDT Tue Mar 17 2026

Light snow is expected late tonight into early Wednesday morning
as a weak clipper system moves across the area. Overall,
forecast remains largely on track. Only minor change is the snow
onset/arrival may be delayed a few hours as it spreads into a
rather dry airmass. This may lower amounts slightly with much of
the area seeing up to one inch with localized 1-2 inches, which
currently looks to favor the southwest cwa. The back edge of the
snow currently appears to be make steady progress east through
the predawn hours with snow ending across northwest IN by mid
morning Wednesday. There also is some uncertainty if the snow
will mix with or change to freezing drizzle as it ends. This
seems to be most favored near the IL/WI state line and into WI
but overall confidence is low. Added a slight chance of freezing
drizzle near the IL/WI state line for now but as trends look
right now, the snow may just end with no mix or changeover.

Temperatures look to warm into the lower/mid 40s for most areas
on Wednesday except for the deeper snowpack areas across the
northwest cwa where temps may stay in the 30s. Temps then look
to drop into the lower 30s Wednesday evening before slowly
rising back into the mid 30s early Thursday morning. These temp
trends are important because another clipper system is expected
to move across the area early Thursday morning. While light, the
precipitation associated with this system has shifted a little
further west and with the temps expected to be just above
freezing, it is expected to be all rain showers. But temp trends
will need to be monitored, especially across the northwest cwa
for any possible freezing rain potential.

Temps will warm into the upper 40s north to upper 50s south on
Thursday and then 50s north to lower/mid 60s south on Friday but
a cold front is expected to move south across the area later
Friday afternoon in Friday evening. This will bring much cooler
temps to the Lake Michigan shore and then cooler temps across
the entire area Friday night. But this will be short-lived as
winds turn back southwest and much warmer air spreads back into
the area Saturday, when high temps will likely be in the 60s
areawide with perhaps some lower 70s in the southwest.

There is quite a bit of uncertainty for temperatures on Sunday
which will be dependent on the timing of a cold front. While
there is quite a bit of ensemble support for very warm
temperatures, the timing of this front could lead to a large
temperature gradient across the area. The blended guidance has
warmed to generally around 60 north to around 70 south. No
changes to these temps at this time. There may also be a low
chance for showers as this front moves across the area. cms

&&

.AVIATION /00Z TAFS THROUGH 06Z THURSDAY/...
Issued at 640 PM CDT Tue Mar 17 2026

A clipper system is expected to bring a period of SN across the
area overnight. The system will be gradually weakening while
also encountering plenty of dry low-level air, so there is some
uncertainty with how quick the SN can saturate down to the
surface. Have delayed the onset time by about one hour (06Z for
ORD/MDW). Once top-down saturation occurs, visibility will
quickly lower into low-end MVFR and IFR levels for several
hours. The SN should end by around sunrise (12Z) Wednesday, with
a small (10 percent) chance of very light FZDZSN for a couple
hours thereafter. Total snow accumulations up to around one inch
are possible. Dry conditions with VFR ceilings/visibility are
then expected though the remainder of the period.

SW winds around 10 knots early this evening will gradually back
S and gust to around 20 knots overnight into Wednesday morning,
though winds may favor just east of south (i.e. 170 degrees)
for a few hours centered around 12Z. Winds should then veer
SSW/SW around 10 knots by late morning and WSW/SW under 10 knots
by Wednesday evening.

Kluber

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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